Diverse forms of fishing, principally those dedicated to sports fishing, both marine and freshwater, use a wide variety of lures with hooks, whose form or characteristics are aimed at attracting the attention of the fish and other prey. Many of these baits try to imitate not only the form of the habitual prey of the fish but also their organoleptic qualities and even their movements. To achieve this, the angler provokes the movement of the lure, either by casting it through the air and rapidly retrieving the line to which it remains attached in the water in an active manner, using a fishing reel for example; or by dragging the lure in the water using the traction of an aquatic vehicle that tows the line, a form of fishing known as trolling lure fishing; or a combination of both. In both cases, but to a greater extent in the trolling lure style, the dragging of the lure creates a great amount of friction between the bait and the water, which augments with the speed, such that the bait must be reasonably resistant to the traction so as not to disintegrate. In other cases, such as the “surf casting” fishing, the bait is attached to a weighted hook and the apparatus is cast from the rod from a fixed position on land. Once the bait has reached the bed, the lure will only undergo limited movements, at the mercy of the currents or the waves and it will act on its own to attract the fish.
In some cases, the lure is composed of elements made from rigid materials that may or may not include articulations, with a certain capacity to navigate below the water. This capacity to navigate is based on the dynamics of the forces produced by the counter-currents that are generated in the water by the dragging of the lure, which creates a motion of such lures that can be rotary (“spinning”), snaking, wavy, vibrant or erratic, and that can even provoke the production of a sound or buzzing (“buzz-baits”). These elements can be endowed with reflective or coloured, and even fluorescent, surfaces that draw the fish's attention to them more readily increasing their attractive effect.
In other cases, as in the case of the most extended form of sea sports fishing, the lures are composed of flexible elements, that are made of soft and/or elastic materials, which as well as freely realising movements in counter-currents, can also recreate movements such as those described above. These lures usually completely or partially imitate to a large degree, the shape of a number of vertebrate and invertebrate aquatic animals, common prey for the majority of sports fish. Furthermore, they can incorporate colours and other types of attractants for the fish, such as chemical stimulants, natural or synthetic, related to the organic systems of the usual prey or to the sensorial mechanisms of the predators.
The object of manufacturing these artificial baits is to substitute the many natural baits, such as insects, worms, molluscs, crustacea, fish and other animal groups, used in both commercial and recreational fishing, whose availability not only depends on its prior capture, but also on its heterogeneous quality and on the intermittent seasonal presence of such creatures. This variability is further conditioned by punctual extrinsic factors, such as the climate, which can augment the efforts and the cost in obtaining such baits to an extraordinary extent. These factors critically influence in the returns of commercial fishing of different species, as well as in the market value of these fish, as well as influencing the sporting activity to an important extent.
The development of artificial baits and lures has been the subject of numerous patents, which have dealt with aspects from: the natural and/or synthetic materials used to manufacture the baits; their shapes/forms, colours and dynamic design; the hormonal, gustatory and olfactory additives used as attractants; the way in which these additives are integrated into the lure (encapsulated, dissolved, embedded, as a coating, etc.); as well as the way to combine in the same lure natural and artificial elements capable of imitating the effects of the baits used, for example, in commercial fishing.
Those lures that attempt to imitate natural baits must try look to achieve a compromise between: their stability when moist (to be able to be hooked, without becoming too soft or disintegrating in the water); the constituency and initial malleability of its matrix; the colour, texture, consistency, flexibility and elasticity; the aroma or attraction; the capacity to retain and diffuse in a controlled manner the attractants; the tensile strengh and tearing strengh; and the dynamic capacity (or capacity to “wriggle”), that to the date of this current patent have not been satisfactorily achieved. Furthermore, as is every day more important and demanded in the market, these must be biodegradable, respecting the environment and innocuous both for humans and for aquatic animals.
In reference to the baits destined for use in commercial fishing, developments have been focused towards the design of chemical attractants for diverse marine species of fish, based in biodegradable substrates, as laid out in the patent application submitted by Cross, Gary (British patent application GB 0212538.3, Oceanbait Ltd. 30 May, 2002).
In the past various types of artificial soft or semi-soft baits have been proposed, which contain attractants for fish that are either natural or artificial. Some of these are made up of: a fleshy mass of plastic; synthetic malleable flexible or rigid plastics (PVCs) capable of accommodating natural or synthetic attractants in their pores; gelatinous biodegradable masses and spongy bodies. With the aim of avoiding the use of rubbery plastics such as the traditional PVC's softened with phtalates, the so-called vinyl's, diverse patents have dealt with trying to create a bait using alimentary and animal sub-products to generate semi-solid plastic and well compacted masses whose own scent is the principal attractant; such as the patent U.S. Pat. No. 4,731,247 of Wolford et al. (1988). In these baits, olfactory stimulants such as the liquidated remains of fish are mixed with a water-soluble cellulose ether and with a plasticiser, in order to form a solid composite that can be used as such or stuffed into the form of a sausage. A serious inconvenience of these baits is that they can only be used exclusively as immobile baits or as bait in traps for fish or crustacea. Due to their poor consistency and stability in humid conditions, it is impossible to use these as bait for the hook of a rod.
In the patent of Prochnow U.S. Pat. No. 4,826,691, 1989 a composition was described as a carrier for attractant additives, composed of a cellulose ether. In another patent, U.S. Pat. No. 5,089,277, 1992, the same author described a bait formed by a sufficiently flexible mass that it could be molded into different shapes and placed around a hook, and that was comprised of a mixture in a sufficiently aqueous solution, of a poly-alkylene-glycol and a cellulose ether such as poly-ethylene-glycol and the carboxy-methylcellulose (CMC). In a new patent, U.S. Pat. No. 5,827,551, 1998, Prochnow also described an attractant formulation for fish, and more specifically for “Black bass”, destined to impregnate or coat a PVC vinyl style lure that could remain attached to the bait during a certain period of time. In this way, the slow liberation of the attractants would be permitted but as in previous cases, these would finally end up dissolving and disappearing, unmasking upon its disappearance, the scent of the PVC and its chemical modifying agents.
In reference to the capacity of the baits to degrade in the environment, the patent of Patrick Riley, WO 96/39861 (19 Dec. 1996) describes a formulation to create a soft biodegradable bait based on a polysaccharide (gellan gum or kelcogel), guar gum and PVC together with plasticising agents, that have the serious inconvenience of the liberation of the plastic in the process. Thus, in the presence of the bait a repellent smell is given off that is rejected by the fish.
The concept of biodegradability can often be misinterpreted. It is considered that something is biodegradable when through the action of microorganisms, it is completely degraded liberating CO2, water, salts, methane and biomass. The biodegradation includes two steps: the depolymerisation and the mineralisation. The disaggregation of a material into more elemental parts does not imply its biodegradation until their molecules have not suffered the aforementioned steps. The plastics such as PVC, possess large molecules that micro-organisms cannot degrade and as such although they may desegregate, they remain in the environment for many years.
The stability of the bait in water is fundamental when it must be used as a lure with a hook, given that dragging it may precipitate its dispersion, dissolution or fragmentation, thereby losing its shape and/or attractive properties. The bites of fish in their many nibbles, as well as the struggle that develops during the catch can also break or unhook the bait with ease. An attempt to combine the biodegradability of the bait with an improvement in the strengh of the plastic matrix from which it is made, as well as retaining its capacity to liberate the attractants in an efficient manner is dealt with in the patent of Donald W. Kelly U.S. Pat. No. 6,174,525 B1 (16 Jan. 2001). In this patent, a matrix of gel was presented that had to be cured by freezing in order to favour the appearance of hydrogen bonds to give greater strength to a mix comprised of: at least one water soluble long chain poly-hydroxy-polymer such as PVA (poly-vinyl alcohol) and optionally Amorphophallus konjac (glucomannan or gum konjac), or a polymeric soluble gum such as the iota-carrageenans, or the gum xanthan, and also an aromatic hydroxyl compound to accelerate the formation of hydrogen bonds from the group of catechol, hydroquinone, galic acid etc. The mix must be elaborated at high temperatures (between 87 and 93° C.), and is shaped while warm along with attractants for fish (Berkley's) to form figures and lures, with the ensuing cost in energy. A further disadvantage with these lures is that in order to obtain sufficient strengh when they are larger than 2 inches, they must be submitted to prior curing, in this case through cycles of freezing and thawing, prolonging the process excessively and with the result the these lures are also partially soluble in water.
The introduction of gelatin gels in patents for fishing baits, was initially motivated by its role as a carrier and agglutinating agent for the additives, taking advantage of its soft texture and its biodegradable nature. This is reflected in the Japonese patent JP2002223670 (K. Saiseki, 13 Aug. 2002) in which a solution of gelatin was incorporated as the main ingredient along with plasticisers and aromatic agents in order to obtain a biodegradable bait, and in which crosslinking agents were used for its hardening. Alternatively in the patent of Shervin R. Brown, U.S. Pat. No. 4,764,383 (16 Aug. 1988) a bait was proposed that was based on gelatin as the main ingredient, along with a plasticising agent such as poly-ethylene-glycol and fish oil, that possesses a texture and elasticity similar to that of a natural bait and that can be cut into pieces that can be hooked on successive occasions. Even gelatin can be used to provide the mass with better consistency and cohesion, as in the patent of Associates of Cape Cod, Inc. (U.S. Pat. No. 6,391,295 B1, 2002) in which the attractant formed by the haemolymph of the “horseshoe crab” frozen and dried, or coagulated, is incorporated into a agglutinate to form a solid, the agglutinate being a gel of the: sodium alginate, gelatin, agar or collagen based adhesive paste.
The use of a gel matrix based on gelatin, has been induced both by the search for a material with a soft texture, that is elastic and malleable, as well as biodegradable, and that has a capacity to diffuse and slowly liberate attractant aromas and molecules. However, in none of the cited cases do the gels or the agglutinates used have on their own, or when mixed together, sufficient cohesion and strengh against tearing, stretching or crushing forces necessary to avoid the breaking or disintegration of the lure, with the consequent loss of efficiency and the added cost of having to continually replace it. Moreover, they are also not apt to be shaped into the form of animals as can be achieved, for example, with PVC. For this reason, attempts have been made to reinforce the gel matrix with diverse fibrous materials such as paper, cotton, woven and non-woven cloth both natural and synthetic, plastics, etc.
With the aim of reinforcing the structure of the gel matrix, the introduction of natural or artificial fibres into the mix was proposed prior to its gelling. The patent U.S. Pat. No. 4,245,420 of W. E. S. Carr (1981) described an amorphous artificial bait made up of a hydrophilic matrix reinforced with fibres and other natural or synthetic materials such as paper, skin, leather, wood, textiles, etc., that are insoluble in water, semi-rigid, flexible and permeable so that attractant substances can diffuse from them. The matrix is solid and semi-rigid, made up of a colloidal solution of warm water, mixed with other macromolecules, and a hydrophilic protein such as gelatin. It was pointed out that the gels can be modified with other gel-like thickening materials such as gums, agar, pectins, carrageenans, proteins, collagen and synthetic polymers. An exclusive example is the use of gelatin along with the inclusion of moisteners such as glycerine. The diffusion of the attractants through the matrix of the bait is prolonged by the incorporation of salts such a NaCl. These baits lack the sufficient mechanical properties (in terms of tensile strengh, tearing strengh, etc.) to be used as soft baits for casting in the same way as soft synthetic baits (vinyl), as well as not being apt to be molded into animal shapes and the fact that they dissolve progressively in the water. The manufacturing process of the gel composite and its subsequent molding must be performed in hot water or at a temperature close to the melting point, to be able to dissolve and maintain the gelatine as a sol. Subsequently the bait must be chilled to solidify, which implies elevated costs of production. In another later patent, W. E. S. Carr, U.S. Pat. No. 4,463,018 (1984) also used a water insoluble matrix comprised of gelatine, agar, Carob bean gum, Celufil and glycerol, and that was reinforced with flexible materials. This is permeable to the diffusion and passage of attractants for the fish, which can be liberated in this way at a controlled rate over a prolonged time period once submerged in the water. The bait comes in the shape of rolled leaves that can be cut into chunks for use. Another example, in which furthermore the attractants are of natural origin, is the case of the patent of Jay B. Burreson U.S. Pat. No. 4,882,174 (21 Nov. 1989) that deals with a natural bait made up of a gel-like matrix of gelatin and/or pectin dissolved in water, and that incorporates ground seafood (herrings) and a layer of a fibrous material such as cotton, and that can be cut into chunks or pieces that are used as bait for the fish. Another example are the patents of the same applicant, U.S. Pat. No. 5,197,219 and U.S. Pat. No. 5,062,235 in which rayon fibres are introduced into the mix with the gelling agents and additives.
In all these cases, the use of fibres and other synthetic strengthening materials, without which the matrix would lack of the necessary mechanical properties, make the molding of the gelatinous matrix difficult. Furthermore, they diminish the possibility of the disintegration and the biodegradability of the product once abandoned in the environment, additionally making it indigestible for the animals. The manufacturing process has also to be performed at raised temperatures to dissolve the gelatine.
An attempt to create a gelatinous matrix of greater strengh to those previously proposed forms the basis of the American patent application of Howard D. Ollis, US 20030066231 April, 2003. In this it is claimed that a biodegradable lure molded into the shape of animals, comprised of a mix of carbohydrates and natural proteins such as casein, serum proteins, gelatin, gluten, soya and albumin can be shaped into the form of small animals. This must be cured in order to augment its strengh and to be able to maintain it attached to the hook. This formulation has the disadvantage that the process of curing is posterior to the molding and lasts between 20 and 50 hours. This curing process provokes the shrinking of the lure up to at least 50% which, along with the fact that the composition requires an elevated temperature for its elaboration and injection molding, constitutes a notable limiting factor for productivity. Furthermore the baits dissolve progressively in water during their use and become unhooked or break after a series of more of 20 casts. Moreover, the tensile strengh does not exceed 1.5 kg (Instron Testing apparatus load/5 speed/200).
On occasion, the use of collagen sausage skins has been mentioned to contain other agglutinated substances in pastes or gels that constitute the bait. For example the use of cured, dried and perforated collagen casing in fishing baits has been referred to (DEVRO) in the patent of P. Morton (U.S. Pat. No. 5,216,829, 1993), with the aim of stuffing into this a mass of ground meat remains and in this way ensuring the slow liberation of molecules and aromas. In the same way, the patent of Teepak U.S. Pat. No. 5,281,425 (K. V. Stribling, 25 Jan. 1994), should be mentioned in which a mass of meat remains that proceed from the boning and preparation of birds, pigs or beef, are stuffed into a collagen casing to make sausages, dried and cured, which are later segmented and sealed, constituting a bait that stimulates the olfaction of marine crustacea.
Hence, there is still a need for state of the art technology to provide an alternative bait to confront the problem of the scarcity, variability and the cost of baits for commercial fishing that heavily condition the economics of such activities. The solution proposed by the present invention consists in producing a universal bait based on collagen fibres that can substitute the usual baits without producing risks for the environment, and that furthermore are of a soft texture, are flexible and malleable, have a good capacity to diffuse and liberate attractant substances, present excellent mechanical properties, principally in as much as their strengh to breakage and to tearing, and that are easy to manipulate, transport and store.